To tell the story of the John Deere 520, one really has to start at Deere’s first tractor aimed at that particular power range, the model “B.” Deere’s entry into the two-bottom plow row crop field first began with production of the model “B” in 1934. After nearly 18 years on the assembly line, the “B” was, and still is, the best selling John Deere tractor of all time.
The model 50 followed the “B” and brought many improvements, including a number of options that made the tractor more capable than its predecessor and others that simply made it more comfortable. Several versions were released and model 50 tractors for contingents of farmers with various and specific needs were engineered and sold. In four years of production, the model 50 sold nearly 33,000 tractors. This was certainly a respectable number, especially considering that the average farmer owned more land and needed more power in his tractor than he did even just five years prior to the model 50’s release.
The improvements that had been made in the 1940s and ‘50s in farming practices, seed and chemicals had led to better yields and lower prices. This caused many farmers to reevaluate their situation, as they were making less money per acre each year. Farmers could cut costs, requiring them to, among other things, look for the most cost-efficient tractor that they could find to keep those costs low. On the other hand, they could farm more land to bring in more money over their fixed costs. These farmers needed more power in their tractors to allow them to get all of the extra work completed. Both groups of farmers continued to be mindful of the features and comfort that a new prospective tractor could provide, as, either way, they were going to be sitting on it for hours on end.
The model “B,” always the tractor for the average to smaller sized farm, was the tractor that many of the first group of farmers was using. In 1956, Deere released its latest installment in that lineage, the 520. Seeing a “B” and a 520 side by side, one can easily see how closely the two tractors are related to each other, but the 520 was much more than a warmed-over version of the previous generations; it was a brand new tractor from grille to drawbar.
The engine of the 520 was completely new. The 4-11/16ths inch bore and 5-1/2 inch stroke were the only things that remained from the engine used on the model 50. Deere’s very capable engineering department had been hard at work in research when the 20 series was in development. One of the areas in which they focused a lot of attention was combustion. Improved combustion can create a much more powerful and efficient engine while saving the customer and producer money by keeping the engine small. The engineers had improved the “cyclone” combustion chamber to the point where they could increase the compression ratio in the engine by more than 30 percent over that used in the 50. They went on to increase the working engine speed by 75 RPM to 1,325 RPM. Then, to keep things reliable and to help generate yet more power, they used aluminum pistons, stronger connecting rods and a stronger crankshaft.
To guarantee that the engine would continue running as well as the day that it left the factory, Deere revamped how the distributor was run. Rather than driving it off of the governor, as had been the previous practice, the distributor was moved to the main case and was driven by the camshaft. This relocation kept timing more precise, as there were fewer ways for the distributor to inherit any slop through engine and component wear.
Where did all of these improvements bring the little 190 cubic inch engine? It seems 38.58 horsepower was now the mark for the gasoline engine—a full 20 percent better than the previous version. LP-gas engines showed a similar improvement and produced 38.09 horsepower at the belt. The all-fuel engine was not as improved, however. In fact, the compression was not increased in these engines and they could produce just 26.61 horsepower, only three horses more than the all-fuel engine in the model 50.
The gasoline and LP-gas versions of the 520 could now be expected to pull a three-bottom plow in most conditions, effectively moving this line of tractors up a class. The improvements did not end at pure power, however, as the engines were also eight percent more economical than those used in the 50. Farmers could now get more work done in less time and use less fuel doing it. What’s not to like?
To make sure that there were no problems with starting the new engine, Deere provided bypass starting. This feature automatically bypassed a resistor in the ignition circuit, allowing 12 volts to enter the coil and distributor when the tractor was being started. This hotter spark made the engine quicker to fire during startup. When the operator released the starter pedal, the bypass was no longer in effect and only six volts were used to make the spark. This lower voltage alleviated the wear on the condenser and points.
To accommodate the increase in power brought to the chassis by the new engine, Deere incorporated a strengthened transmission and more robust final drives into the 520. A new and higher final drive ratio was used, keeping the 520 at the same speed as the 50 in the field despite the increase in engine speed. Larger brakes were used, allowing both for better performance and longer brake life.
A foot-operated PTO pedal replaced the old hand-operated lever for the 520. This allowed the operator to keep his hands on the rest of the controls. The new control offered three positions: positive stop to keep implements still; neutral, which allowed the operator to turn the PTO by hand when connecting or adjusting implements; and positive engaged for operating the implement. Deere’s engineers also increased the capacity of the PTO clutch.
We have covered the middle and rear of the 520 pretty well; let’s move to the front. To match the front end stability of tractors with power steering, Deere increased the weight of the manual steering pedestal to more closely match that of the power steering version. The front end support had been revised and strengthened to accommodate more front mounted implements as well as the new front end weights that were introduced for the series. The fuel tank was expanded and could now hold 18 gallons, keeping you in the field longer.
That was quite a list of improvements and when combined, they created a tractor that was quite an improvement over the 50. There was one more improvement, though, which really defined the series. The new Custom Powr-Trol hydraulic system was originally tested on model 80 tractors and proved to be a powerful advancement in hydraulics technology. The system allowed up to three hydraulic circuits to be controlled separately. This combined with the new universal three-point hitch to provide load and depth control in varying field conditions.
The 520 was only ever produced as a row crop tractor. The tractor was produced to be attractive to farmers of nearly any means and could be ordered as little more than an engine on wheels. Almost everything was an option on these tractors, including “live” 540 RPM PTO, power steering, the Float-Ride seat, single or dual remote hydraulics, and front or rear rockshaft. Other options included fenders, speed hour meter, rear exhaust, vertical air stack, fuel gauge and a cigarette lighter. The tractor was extremely customizable and could be had with nothing or everything as a farmer saw fit for his farm and his pocketbook.
Of those options, power steering and the Float-Ride seat were two of the most popular. The power steering system had been significantly advanced over previous generations and gave an operator smooth control of the tractor without a fight. The Float-Ride seat could be adjusted to the weight of the operator and did a very good job of preserving his spine over rough ground. These were offered for an additional $35 and came in either yellow or black.
Standard front wheel equipment on the 520 was a fixed dual front. If this was insufficient, the buyer could also choose from regular or heavy duty Roll-O-Matic, single front wheels of 6.50-16 or 9.00-10 sizes, an adjustable front axle which allowed treads from 48 to 80 inches or a 38 inch fixed tread front axle.
The farmer had a number of choices for equipment on the rear axle as well. Standard equipment was 12.4-36 inch rear tires, but 13.9-39 or 12.4-38 inch tires or 11-38 inch rice and cane tread tires were available as options. Standard rims came with these tires and any of them could also be ordered with special offset wheels. These allowed the farmer to set the rear tread six inches narrower or wider than the standard wheels could provide. Power adjusted rear wheels were also available as an option, but only for the 36-inch rear tires. Those who needed all of the grip that they could get or still didn’t trust rubber to get the job done could call in a special order for steel wheels.
Also available were 9-42 inch tires on the 520. This was a unique option and ordering these tires installed on your new tractor automatically included offset rear wheels and long rear axles as well. These long rear axles were another option and allowed a maximum of 104 inch rear tread. The axles also had a larger diameter and larger bearings to keep the extra load from causing any problems. The rear axle housing on tractors with this option was unique as well to accommodate the axles. Many tractors that were configured with these parts also included a single front wheel and are known colloquially as “Vegetable Specials.” This was certainly an appropriate moniker, but was not official.
More than 13,000 model 520 tractors were built and over 12,000 of those were gasoline models. A total of 764 LP-gas 520s were manufactured, leaving only 244 all-fuel models. This really is not surprising. By the time that the 520 was being produced, tractor fuel, kerosene and other heavy fuels were on their way out. Gasoline had become cheaper and more economical and the sales figures prove that it was taking over the small tractor market. The 26.61 horsepower produced by the all-fuel engine in the 520 was actually less than the 420’s gasoline engine could make, making one wonder if the all-fuel tractors which sold all went to tractor fuel plants. If you happen to have a stockpile of kerosene and would like to find one of these oddities to complete your 20 series collection, good luck to you. Many of them were probably converted to gasoline tractors after being recorded as all-fuels in the Deere registries but before being sold, others were probably converted later in life as gasoline became even more common and less expensive and about a third of the tractors were exported when they were first sold. If you still want to look, start in the southeastern United States, where tractor fuel lived on the longest.
After a little over a year of production, the 520 (and the rest of the series) underwent a few updates and modifications and out rolled the 1958 models. Serial number 5208100 was the first to receive a new plastic covered steering wheel, black painted dash panel and sealed-beam lights. The clutch, rockshaft, hydraulic controls and steering system were updated as well. The option of an axle-mounted step was made standard equipment and two new options—a pre-screener/pre-cleaner and left-handed hydraulic controls were added.
The 520 met its production end in July of 1958 when it was replaced by the 530. The 530 showcased new styling, but was mechanically indistinguishable from the 520. The 520 was at the low end of the tractor power spectrum when it was produced. Small farms were not completely gone, however, and many people needed a tractor like the 520 as their primary machine. Other farmers of larger operations found the 520 to be a very useful little tractor for doing odd jobs, but soon found that its 190 cubic inches were capable of a lot more than they might have expected, earning the tractor some much deserved respect.
The Industrial Division at John Deere marketed the 520, but no changes were made to tractors sold for industrial use. Because the Industrial Division offered the tractor, it is possible that a few left the factory painted entirely in industrial or John Deere yellow. I know of no tractors painted in this way, but it is possible and we would love to hear about any 520 that was factory-painted in yellow. Be careful, though, as a yellow primer coat was often used on components during this era at John Deere, so scraping old paint may not tell you the whole story.
Barring a 520 with the unique paint scheme mentioned in the last paragraph, they were all painted green and yellow. One point of confusion persists, though. Tractors with serial numbers below 5208100 left the factory with black head and tail lights, green dash panels and black generators. Model 520 number 5208100 and above (1958 models) also had black head and tail lights, but had black dash panels and green generators. I can’t force you to paint your tractor this way, but that is how it would have been when it was brand new. The seat cushions on all 520 tractors were available in black or yellow, so go with what you know is original to that particular tractor or use whichever you prefer. Of course, never cut costs on your restoration by purchasing cut-rate decals; you’ll soon rue the day.
Unfortunately, the 520 is often seen as an unexceptional middle child, outshone by its beefier big brothers and cuter little ones. This is unfortunate, as the 520 certainly deserves more respect than that. The 520 showed a knack for longevity and, due to the relatively light work that a lot of them spent their lives doing, many are still in sound mechanical condition. They pack a lot of big tractor punch into a fairly small frame. While it only came as a row crop model, there are plenty of engine/front end/rear wheel combinations out there to make for some rare tractors. Should you decide to purchase a 520, your only problem lies in trying to pry it out of the hands of its current, and probably very satisfied, owner.